With the rise in the use of laparoscopic surgery, it has been determined that there are additional needs necessary for operating a typical laparoscopic trocar. Specifically, it has been noticed that it may be desirable to convert the outer opening of the trocar cannula from a larger diameter to a smaller diameter. This smaller opening creates a seal about smaller diameter instruments used after puncturing the trocar with a laparoscopic obturator. Exemplary of such valving "reducer" mechanisms are U.S. patent application Ser. No. 618,325, now U.S. Pat. No. D 335,536, assigned to Ethicon, Inc., and U.S. patent application Ser. No. 877,903, filed May 1, 1992, similarly assigned to Ethicon, Inc., the assignee of the present invention. Each of these patent and patent application is herein incorporated by reference.
Also, there have been placed in the market products such as the Origin trocar, produced by Origin Medisystems of Palo Alto, California which contains an integral reducer cap, allowing a 10 mm opening to be converted to a 7 mm opening or a 5 mm opening. Such a system uses an integral sliding mechanism, which allows the seal to be rotated about a corner of the trocar cannula handle and emplaced over the 10 mm opening created in the obturator handle. However, this arrangement is quite cumbersome for surgeons. This is so because the sliding mechanics of the seals make it such that the seals are incapable of being rapidly and easily put into place. The user must move his or her thumb from the side of the instrument and around the top of the cannula handle over the opening in the cannula handle. This can be quite a tricky one handed maneuver.
What is desirable therefore is a reducer system which allows the user to rapidly and easily place the reduced opening in the reducer system over the opening of the trocar cannula. Also, it is an object of the invention to provide an integral system wherein there is no need to search on the surgical stand for a reducer. It is desirable, that is, to have the reducer attached at all times to the trocar cannula handle. Finally, it is an object of this invention to allow the user to convert the system not only from a larger diameter opening to a smaller diameter opening in a easy and readily operable fashion, but also to convert from a smaller opening to the larger opening in a similar easily operable and manageable fashion.